code: def test_fallback_with_stringio():
      def slow(s):
          return s.read()
  
      def fast(s):
          s.read()
          raise ValueError()
  
      pxy = _FunctionProxy(fast=fast, slow=slow)
      assert pxy(StringIO("hello")) == "hello"
  
imports: import inspect
  from functools import partial
  from io import StringIO
  import numpy
  import pytest
  from cudf.pandas.fast_slow_proxy import _fast_arg, _FunctionProxy, _slow_arg, _transform_arg, _Unusable, make_final_proxy_type, make_intermediate_proxy_type
label_desc: Use image node_id 11 for calling a global function with example usage: test_fallback_with_stringio() and returns: s